Three ethylene biosynthesis related genes, EjACS1, EjACO1, and EjACO2, were cloned from the non-climacteric loquat fruit (Eriobotrya japonica Lindl. cv. Luoyangqing). Real-time quantitative PCR (Q-PCR) analysis showed the specific expression of the EjACS1 and EjACO1 genes in fruit, whereas EjACO2 was also expressed in leaves and petals. The expression pattern of EjACO2 was consistent with ethylene production during fruit development, which reached a peak when the fruit color was turning. EjACS1, EjACO1, and EjACO2 all showed low transcript levels throughout 20Â°C storage in the postharvest ripening loquat. This is the first time that the expression of ethylene biosynthesis related genes has been studied in loquat fruit. Climacteric increases in ethylene production and respiration rate were observed during the development of loquat fruit, and EjACO2 may play an important role in this process.